Radio frequency module and communication device

ABSTRACT

A radio frequency module includes: a module board; a first semiconductor device containing a first power amplifier and a second power amplifier, the first power amplifier being configured to amplify a radio frequency signal of a first communication band, the second power amplifier being configured to amplify a radio frequency signal of a second communication band, the second communication band being different from the first communication band; and a second semiconductor device containing a control circuit configured to control the first power amplifier and the second power amplifier. In the radio frequency module, the first semiconductor device and the second semiconductor device are stacked together and disposed on the module board.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on and claims priority of JapanesePatent Application No. 2020-061798 filed on Mar. 31, 2020. The entiredisclosure of the above-identified application, including thespecification, drawings and claims is incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a radio frequency (RF) module and acommunication device.

BACKGROUND

In mobile communication devices such as a mobile phone, the arrangementconfiguration of circuit components included in radio frequencyfront-end modules is becoming complex, particularly with developments inmultiband technologies.

U.S. Patent Application Publication No. 2015/0133067 discloses afront-end module including a power amplifier, a switch, a filter, etc.in a package.

SUMMARY Technical Problems

Further miniaturization is desirable for such conventional front-endmodules.

In view of the above, the present disclosure is presented to provide aradio frequency module and a communication device which are capable ofimplementing miniaturization.

Solutions

A radio frequency module according to one aspect of the presentdisclosure includes: a module board; a first semiconductor devicecontaining a first power amplifier and a second power amplifier, thefirst power amplifier being configured to amplify a radio frequencysignal of a first communication band, the second power amplifier beingconfigured to amplify a radio frequency signal of a second communicationband, the second communication band being different from the firstcommunication band; and a second semiconductor device containing acontrol circuit configured to control the first power amplifier and thesecond power amplifier. In the radio frequency module, the firstsemiconductor device and the second semiconductor device are stackedtogether and disposed on the module board.

Advantageous Effects

With the radio frequency module according to one aspect of the presentdisclosure, it is possible to implement miniaturization.

BRIEF DESCRIPTION OF DRAWINGS

These and other advantages and features will become apparent from thefollowing description thereof taken in conjunction with the accompanyingDrawings, by way of non-limiting examples of embodiments disclosedherein.

FIG. 1 is a diagram illustrating a circuit configuration of a radiofrequency module and a communication device according to Embodiment 1.

FIG. 2 illustrates a plan view of a radio frequency module according toEmbodiment 1.

FIG. 3 illustrates a cross-sectional view of the radio frequency moduleaccording to Embodiment 1.

FIG. 4 illustrates a plan view of a radio frequency module according toEmbodiment 2.

FIG. 5 illustrates a cross-sectional view of the radio frequency moduleaccording to Embodiment 2.

DESCRIPTION OF EMBODIMENTS

The following describes in detail embodiments of the present disclosurewith reference to the drawings. Each of the embodiments described belowillustrates a general or specific example. The numerical values, shapes,materials, structural components, the arrangement and connection of thestructural components, and so on, illustrated in the followingembodiments are mere examples, and therefore do not limit the presentdisclosure.

It should be noted that, each of the diagrams is a schematic diagram towhich an emphasis, an omission, or an adjustment of ratios has beenapplied as appropriate to illustrate the present disclosure, and thus isnot necessarily strictly illustrated. There are instances where theshapes, positional relationships, and ratios illustrated in the diagramsare different from the actual shapes, actual positional relationships,and actual ratios. In each of the diagrams, substantially the samestructural components are denoted by the same reference signs, andredundant description may be omitted or simplified.

In each of the diagrams described below, the x-axis and the y-axis areorthogonal to each other on a plane parallel to the principal surface ofthe module board. In addition, the z-axis is perpendicular to theprincipal surface of the module board. The positive direction of thez-axis indicates an upward direction and the negative direction of thez-axis indicates a downward direction.

In addition, in the circuit configuration according to the presentdisclosure, the meaning of “to be connected” includes not only to bedirectly connected via a connection terminal and/or a line conductor,but also to be electrically connected via other circuit elements. Themeaning of “to be connected between A and B” is to be connected to bothA and B between A and B.

In addition, in the component arrangement according to the presentdisclosure, the meaning of “in a plan view of a module board” is to viewan object by orthographically projecting the object on the xy-plane fromthe z-axis positive side. The meaning of “A overlaps B in a plan view ofa module board” is that at least a portion of the region of Aorthographically projected on the xy-plane overlaps at least a portionof the region of B orthographically projected on the xy-plane. Themeaning of “A does not overlap B in a plan view of a module board” isthat the region of A orthographically projected on the xy-plane does notoverlap any portion of the region of B orthographically projected on thexy-plane. The meaning of “A is disposed between B and C” is that atleast one of a plurality of line segments connecting arbitrary points inB and arbitrary points in C passes through A. Terms indicating therelationships between elements such as “parallel” and “perpendicular” donot represent only the strict meanings but include also a substantiallyequivalent range, such as a difference of approximately several percent.

The meaning of “a component is disposed on a board” includes not onlythat the component is disposed on the board in a state in which thecomponent is in contact with the board, but also that the component isdisposed above the board without contacting the board (e.g., thecomponent is stacked on another component disposed on the board), andthat a portion or the whole of the component is embedded in the board.The meaning of “a component is disposed on a principal surface of aboard” includes not only that the component is disposed on the principalsurface in a state in which the component is in contact with theprincipal surface of the board, but also that the component is disposedabove the principal surface of the board without contacting theprincipal surface, and that a portion of the component is embedded inthe board from a principal surface side.

Embodiment 1 1.1 Circuit Configuration of Radio Frequency Module 1 andCommunication Device 5

The following describes circuit configurations of radio frequency module(or RF front-end circuitry) 1 and communication device 5 according tothe present embodiment. FIG. 1 is a diagram illustrating a circuitconfiguration of radio frequency module 1 and communication device 5according to Embodiment 1.

1.1.1 Circuit Configuration of Communication Device 5

First, the circuit configuration of communication device 5 will bedescribed. As illustrated in FIG. 1, communication device 5 according tothe present embodiment includes radio frequency module 1, antenna 2,radio frequency integrated circuit (RFIC) 3, and baseband signalprocessing circuit (BBIC) 4.

Radio frequency module 1 transfers a radio frequency signal betweenantenna 2 and RFIC 3. The internal configuration of radio frequencymodule 1 will be described later.

Antenna 2 is connected to antenna connection terminal 100 of radiofrequency module 1, and transmits a radio frequency signal that has beenoutput from radio frequency module 1. In addition, antenna 2 receives aradio frequency signal from the outside, and outputs the received radiofrequency signal to radio frequency module 1.

RFIC 3 is one example of a signal processing circuit that processes aradio frequency signal. More specifically, RFIC 3 performs signalprocessing, by down-conversion or the like, on a radio frequencyreception signal input via the reception path of radio frequency module1, and outputs the reception signal generated by the signal processingto BBIC 4. In addition, RFIC 3 performs signal processing, byup-conversion or the like, on a transmission signal input from BBIC 4,and outputs the radio frequency transmission signal generated by thesignal processing to the transmission path of radio frequency module 1.In addition, RFIC 3 includes a controller that controls a switch, anamplifier, etc. included by radio frequency module 1. It should be notedthat a portion or the whole of the functions of RFIC 3 as a controllermay be located outside RFIC 3, and may be located, for example, in BBIC4 or radio frequency module 1.

BBIC 4 is a baseband signal processing circuit that performs signalprocessing using an intermediate frequency band including frequencieslower than frequencies of a radio frequency signal that is transferredby radio frequency module 1. The signals processed by BBIC 4 include,for example, an image signal for image display and/or a sound signal fortelephone conversation via a speaker.

It should be noted that, in communication device 5 according to thepresent embodiment, antenna 2 and BBIC 4 are not indispensablecomponents.

1.1.2 Circuit Configuration of Radio Frequency Module 1

Next, a circuit configuration of radio frequency module 1 will bedescribed. As illustrated in FIG. 1, radio frequency module 1 includespower amplifiers 11 and 12, low noise amplifier 21, switches 51 to 54,control circuit 55, duplexers 61 to 63, transformers 71 and 72, matchingcircuit (matching network (MN)) 73, antenna connection terminal 100, aplurality of radio frequency input terminals 110, radio frequency outputterminal 121, and control terminal 131.

Antenna connection terminal 100 is one example of an external-connectionterminal. Antenna connection terminal 100 is connected to antenna 2.

The plurality of radio frequency input terminals 110 are each oneexample of the external-connection terminal, and is a terminal forreceiving a plurality of radio frequency transmission signals fromoutside radio frequency module 1. According to the present embodiment,the plurality of radio frequency input terminals 110 include four radiofrequency input terminals 111 to 114.

As the plurality of radio frequency signals that the plurality of radiofrequency input terminals 110 receive from outside, for example, radiofrequency signals of mutually different communication systems and/orradio frequency signals of mutually different communication bands may beused.

The communication system means a communication system established usinga radio access technology (RAT). According to the present embodiment,for example, the 5th generation new radio (5GNR) system, the long termevolution (LTE) system, a wireless local area network (WLAN) system,etc. may be used as the communication system. However, the communicationsystem is not limited to these examples.

The communication band means a frequency band predefined for acommunication system by standard-setting organizations or the like suchas the 3rd generation partnership project (3GPP), the institute ofelectrical and electronics engineers (IEEE), etc.

It should be noted that a total number of the plurality of radiofrequency input terminals 110 is not limited to four. For example, thetotal number of the plurality of radio frequency input terminals 110 maybe less than four or more than four.

Radio frequency output terminal 121 is one example of theexternal-connection terminal, and is a terminal for providing aplurality of radio frequency reception signals to the outside of radiofrequency module 1. It should be noted that radio frequency module 1 mayinclude a plurality of radio frequency output terminals.

Control terminal 131 is one example of the external-connection terminal,and is a terminal for receiving a control signal from the outside ofradio frequency module 1. As the control signal, for example, a signalfor controlling power amplifiers 11 and 12 may be used.

Power amplifier 11 is one example of a first power amplifier, and iscapable of amplifying a plurality of radio frequency signals received bythe plurality of radio frequency input terminals 110. Here, poweramplifier 11 is capable of amplifying a radio frequency signal ofcommunication band A that has been input from radio frequency inputterminal 111 and/or radio frequency input terminal 112 via switch 54.

Power amplifier 12 is one example of a second power amplifier, and iscapable of amplifying a plurality of radio frequency signals received bythe plurality of radio frequency input terminals 110. Here, poweramplifier 12 is capable of amplifying radio frequency signals ofcommunication bands B and C that have been input from radio frequencyinput terminal 113 and/or radio frequency input terminal 114 via switch54.

Each of power amplifiers 11 and 12 is a multistage amplifier. In otherwords, each of power amplifiers 11 and 12 includes a plurality ofamplifying elements connected in a cascade arrangement. Morespecifically, power amplifier 11 includes amplifying element 11 a thatcorresponds to an input stage and amplifying element 11 b thatcorresponds to an output stage. In addition, power amplifier 12 includesamplifying element 12 a that corresponds to an input stage andamplifying element 12 b that corresponds to an output stage. It shouldbe noted that a total number of stages of each of power amplifiers 11and 12 is not limited to two, but may be three or more. Power amplifier11 and/or power amplifier 12 may have a single stage structure.

Power amplifier 11 and/or power amplifier 12 may amplify a radiofrequency signal by transforming the radio frequency signal into adifferential signal (i.e., a complementary signal). Such power amplifier11 and/or power amplifier 12 as described above are each referred to asa differential amplifier in some cases. In this case, power amplifier 11and/or power amplifier 12 may output a differential signal.

Transformer 71 is connected between power amplifier 11 and transmissionfilter 61T. More specifically, transformer 71 is connected between anoutput terminal of power amplifier 11 and terminal 511 of switch 51.Transformer 71 is capable of matching the impedance of power amplifier11 with the impedance of transmission filter 61T. It should be notedthat, under the condition that power amplifier 11 outputs a differentialsignal, transformer 71 functions as a balun (balanced to unbalancedtransformer element).

Transformer 72 is connected between power amplifier 12 and transmissionfilters 62T and 63T. More specifically, transformer 72 is connectedbetween the output terminal of power amplifier 12 and terminal 512 ofswitch 51. Transformer 72 is capable of matching the impedance of poweramplifier 12 with the impedance of transmission filters 62T and 63T. Itshould be noted that, under the condition that power amplifier 12outputs a differential signal, transformer 72 functions as a balun(balanced to unbalanced transformer element).

matching circuit 73 is connected between low noise amplifier 21 andreception filters 61R to 63R. More specifically, matching circuit 73 isconnected between an input terminal of low noise amplifier 21 andterminal 521 of switch 52. Matching circuit 73 matches the impedance oflow noise amplifier 21 with the impedance of reception filters 61R and63R.

Low noise amplifier 21 is capable of amplifying a plurality of radiofrequency signals received by antenna connection terminal 100. Here, lownoise amplifier 21 is capable of amplifying radio frequency signals ofcommunication bands A to C which have been input through antennaconnection terminal 100 via switch 53, duplexers 61 to 63, and switch52. The radio frequency signals amplified by low noise amplifier 21 areoutput to radio frequency output terminal 121. The configuration of lownoise amplifier 21 is not specifically limited.

Duplexer 61 passes a radio frequency signal of communication band A.Duplexer 61 transfers a transmission signal and a reception signal ofcommunication band A in a frequency division duplex (FDD) system.Duplexer 61 includes transmission filter 61T and reception filter 61R.

Transmission filter 61T is connected between switch 51 and antennaconnection terminal 100. Transmission filter 61T passes a signal in atransmission band of communication band A among the radio frequencytransmission signals that have been amplified by power amplifier 11.

Reception filter 61R is connected between switch 52 and antennaconnection terminal 100. Reception filter 61R passes a signal in areception band of communication band A among the radio frequencyreception signals that have been input through antenna connectionterminal 100.

Duplexer 62 passes a radio frequency signal of communication band B.Duplexer 62 transfers a transmission signal and a reception signal ofcommunication band B in the FDD system. Duplexer 62 includestransmission filter 62T and reception filter 62R.

Transmission filter 62T is connected between switch 51 and antennaconnection terminal 100. Transmission filter 62T passes a signal in atransmission band of communication band B among the radio frequencytransmission signals that have been amplified by power amplifier 12.

Reception filter 62R is connected between switch 52 and antennaconnection terminal 100. Reception filter 62R passes a signal in areception band of communication band B among the radio frequencyreception signals that have been input through antenna connectionterminal 100.

Duplexer 63 passes a radio frequency signal of communication band C.Duplexer 63 transfers a transmission signal and a reception signal ofcommunication band C in the FDD system. Duplexer 63 includestransmission filter 63T and reception filter 63R.

Transmission filter 63T is connected between switch 51 and antennaconnection terminal 100. Transmission filter 63T passes a signal in atransmission band of communication band C among the radio frequencytransmission signals that have been amplified by power amplifier 12.

Reception filter 63R is connected between switch 52 and antennaconnection terminal 100. Reception filter 63R passes a signal in areception band of communication band C among the radio frequencyreception signals that have been input through antenna connectionterminal 100.

As communication band A, for example, a communication band that belongsto a high band group can be used. The high band group is a frequencyband group including a plurality of communication bands, and is higherthan the middle band group. The high band group has, for example, afrequency range from 2.4 GHz to 2.8 GHz. The high band group includes,for example, a communication band for LTE such as band B7 (uplink: 2500MHz to 2570 MHz, downlink: 2620 MHZ to 2690 MHz).

As communication bands B and C, for example, a communication band thatbelongs to a middle band group can be used. The middle band group is afrequency band group including a plurality of communication bands, andis lower than the high band group. The middle band group has, forexample, a frequency range from 1.5 GHz to 2.2 GHz. The middle bandgroup includes, for example, communication bands for LTE such as band B1(uplink: 1920 MHz to 1980 MHz, downlink: 2110 MHz to 2170 MHz), band B39(1880 MHz to 1920 MHz), and band B66 (uplink: 1710 MHz to 1780 MHz,downlink: 2110 MHz to 2200 MHz).

Switch 51 is one example of the first switch, and is connected betweentransmission filters 61T to 63T and power amplifiers 11 and 12.Specifically, switch 51 includes terminals 511 to 515. Terminal 511 ofswitch 51 is one example of the first terminal. Terminal 511 isconnected to the output terminal of power amplifier 11. Terminal 512 ofswitch 51 is one example of the second terminal. Terminal 512 isconnected to the output terminal of power amplifier 12. Terminals 513 to515 of switch 51 are connected respectively to transmission filters 61Tto 63T. In the above-described connection configuration, switch 51 iscapable of connecting and disconnecting terminal 511 and terminal 513,and connecting one of terminal 514 and terminal 515 to terminal 512,based on a control signal from RFIC 3, for example. In other words,switch 51 is capable of connecting and disconnecting power amplifier 11and transmission filter 61T, and also capable of switching connection ofpower amplifier 12 between transmission filter 62T and transmissionfilter 63T. Switch 51 is implemented as, for example, amultiple-connection switching circuit, and referred to as a bandselection switch.

Switch 52 is connected between low noise amplifier 21 and receptionfilters 61R to 63R. Specifically, switch 52 includes terminals 521 to524. Terminal 521 of switch 52 is connected to an input terminal of lownoise amplifier 21. Terminals 522 to 524 of switch 52 are connectedrespectively to reception filters 61R to 63R. In the above-describedconnection configuration, switch 52 is capable of connecting one ofterminals 522 to 524 to terminal 521, based on a control signal fromRFIC 3, for example. In other words, switch 52 is capable of switchingconnection of low noise amplifier 21 between reception filter 61R,reception filter 62R, and reception filter 63R. Switch 52 is implementedas, for example, a single-pole triple-throw (SP3T) switching circuit,and is referred to as a low noise amplifier (LNA) IN switch.

Switch 53 is connected between antenna connection terminal 100 andduplexers 61 to 63. Specifically, switch 53 includes terminals 531 to534. Terminal 531 of switch 53 is connected to antenna connectionterminal 100. Terminals 532 to 534 of switch 53 are connectedrespectively to duplexers 61 to 63. In the above-described connectionconfiguration, switch 53 is capable of connecting at least one ofterminals 532, 533, or 534 to terminal 531, based on a control signalfrom RFIC 3, for example. More specifically, switch 53 is capable ofconnecting and disconnecting antenna 2 and duplexer 61, connecting anddisconnecting antenna 2 and duplexer 62, and connecting anddisconnecting antenna 2 and duplexer 63. Switch 53 is implemented as,for example, a multiple-connection switching circuit, and referred to asan antenna switch.

Switch 54 is one example of the second switch, and is connected betweena plurality of radio frequency input terminals 110 and power amplifiers11 and 12. Specifically, switch 54 includes terminals 541 to 546.Terminal 541 of switch 54 is one example of the third terminal, and isconnected to an input terminal of power amplifier 11. Terminals 542 and543 of switch 54 are connected respectively to radio frequency inputterminals 111 and 112. Terminal 544 of switch 54 is one example of thefourth terminal, and is connected to an input terminal of poweramplifier 12. Terminals 545 and 546 of switch 54 are connectedrespectively to radio frequency input terminals 113 and 114. In theabove-described connection configuration, switch 54 is capable ofconnecting one of terminals 542 and 543 to terminal 541, and capable ofconnecting one of terminals 545 and 546 to terminal 544, based on acontrol signal from RFIC 3, for example. In other words, switch 54 iscapable of switching connection of power amplifier 11 between radiofrequency input terminal 111 and radio frequency input terminal 112, andcapable of switching connection of power amplifier 12 between radiofrequency input terminal 113 and radio frequency input terminal 114.Switch 54 is implemented as, for example, a multiple-connectionswitching circuit, and referred to as a transmission input switch.

Control circuit 55 is connected to control terminal 131. Control circuit55 receives a control signal from RFIC 3 via control terminal 131, andoutputs the control signal to power amplifiers 11 and 12. It should benoted that control circuit 55 may output the control signal to othercircuit components.

It should be noted that one or some of the circuit elements illustratedin FIG. 1 need not necessarily be included in radio frequency module 1.For example, it is sufficient if radio frequency module 1 includes atleast power amplifiers 11 and 12, and one of switch 51 and controlcircuit 55. Radio frequency module 1 need not necessarily include theother circuit elements.

With the circuit configuration of radio frequency module 1, atransmission signal and a reception signal can be communicated in theFDD system. However, the circuit configuration of the radio frequencymodule according to the present disclosure is not limited to thisexample. For example, the radio frequency module according to thepresent disclosure may have a circuit configuration capable ofperforming communication of a transmission signal and a reception signalin a time division duplex (TDD) system, or may have a circuitconfiguration capable of performing communication of a transmissionsignal and a reception signal in both the FDD system and the TDD system.

1.2 Component Arrangement of Radio Frequency Module 1

The following describes in detail the component arrangement of radiofrequency module 1 configured as described above, with reference to FIG.2 and FIG. 3.

FIG. 2 illustrates a plan view of radio frequency module 1 according toEmbodiment 1. In FIG. 2, (a) illustrates a view when principal surface91 a of module board 91 is viewed from the z-axis positive side, and (b)illustrates a view when principal surface 91 b of module board 91 isviewed through from the z-axis positive side. FIG. 3 illustrates across-sectional view of radio frequency module 1 according toEmbodiment 1. The cross-sectional surface of radio frequency module 1illustrated in FIG. 3 is a cross-sectional surface taken along lineiii-iii of FIG. 2.

As illustrated in FIG. 2 and FIG. 3, radio frequency module 1 furtherincludes module board 91, ground electrode patterns 92, and a pluralityof bump electrodes 150, in addition to the circuit components thatcontain the circuit elements illustrated in FIG. 1.

Module board 91 includes principal surface 91 a and principal surface 91b on opposite sides thereof. As module board 91, for example, a lowtemperature co-fired ceramic (LTCC) board having a stacked structureincluding a plurality of dielectric layers, a high temperature co-firedceramic (HTCC) board, a component built-in board, a board including aredistribution layer (RDL), or a printed board or the like can be used.However, module board 91 is not limited to these examples.

Principal surface 91 a is one example of the first principal surface,and is referred to as an upper surface or a front surface in some cases.As illustrated in (a) in FIG. 2, semiconductor device 10 that containspower amplifiers 11 and 12, semiconductor device 50 that contains switch51 and control circuit 55, duplexers 61 to 63, and matching circuit 73are disposed on principal surface 91 a.

Semiconductor device 10 is disposed on principal surface 91 a, andsemiconductor device 50 is stacked on semiconductor device 10. At thistime, in a plan view of module board 91, a footprint of semiconductordevice 50 overlaps both a footprint of power amplifier 11 and afootprint of power amplifier 12 contained in semiconductor device 10.More specifically, the footprint of semiconductor device 50 overlapsboth a footprint of amplifying element 11 a and a footprint ofamplifying element 12 a which correspond to the input stage of poweramplifiers 11 and the input stage of power amplifier 12, respectively.However, semiconductor device 50 does not overlap amplifying element 11b corresponding to the output stage of power amplifiers 11 or amplifyingelement 12 b corresponding to the output stage of power amplifier 12.

The semiconductor device is an electronic component including anelectronic circuit formed on the front surface and inside of asemiconductor chip (also referred to as a die), and is also referred toas a semiconductor integrated circuit. The semiconductor device is, forexample, configured by a complementary metal oxide semiconductor (CMOS),and specifically, may be fabricated by silicon on insulator (SOI)processing. With this, it is possible to manufacture a semiconductordevice at a low manufacturing cost. It should be noted that thesemiconductor device may include at least one of GaAs, SiGe, or GaN.This allows implementation of a high-quality semiconductor device.

Each of duplexers 61 to 63 may be, for example, any of a surfaceacoustic wave filter, an acoustic wave filter using a bulk acoustic wave(BAW), an LC resonant filter, and a dielectric filter, but not limitedto these filters.

Matching circuit 73, for example, includes an inductor and/or capacitor,and is implemented using a surface mounted device (SMD). It should benoted that matching circuit 73 may be formed in module board 91, and maybe implemented using an integrated passive device (IPD).

Principal surface 91 b is one example of the second principal surface,and is referred to as a lower surface or a rear surface in some cases.As illustrated in (b) in FIG. 2, semiconductor device 20 that containslow noise amplifier 21 and switch 52, switches 53 and 54, transformers71 and 72, and the plurality of bump electrodes 150 are disposed onprincipal surface 91 b.

Switch 53 is disposed in proximity to bump electrode 150 that functionsas antenna connection terminal 100 among the plurality of bumpelectrodes 150.

Switch 54 is disposed in proximity to bump electrodes 150 that functionas a plurality of radio frequency input terminals among the plurality ofbump electrodes 150. In a plan view of module board 91, a footprint ofswitch 54 overlaps a footprint of semiconductor device 10. Morespecifically, in a plan view of module board 91, the footprint of switch54 overlaps at least one of the footprint of amplifying element 11 acorresponding to the input stage of power amplifier 11 or a footprint ofamplifying element 12 a corresponding to the input stage of poweramplifier 12. However, the footprint of switch 54 does not overlap afootprint of amplifying element 11 b corresponding to the output stageof power amplifier 11 or the footprint of amplifying element 12 bcorresponding to the output stage of power amplifier 12.

It should be noted that, although switches 53 and 54 are not containedin semiconductor device 20 but disposed separately on principal surface91 b according to the present embodiment, switch 53 and/or switch 54 maybe contained in semiconductor device 20.

Transformers 71 and 72 are each contained in module board 91. Morespecifically, transformers 71 and 72 are each provided inside moduleboard 91 on a principal surface 91 b side. It should be noted thattransformer 71 and/or transformer 72 may be surface-mounted on principalsurface 91 a or 91 b as chip circuit components.

Ground electrode patterns 92 are provided inside module board 91 andconnected physically to bump electrode 150 set to a ground potential,for example. Ground electrode patterns 92 are disposed betweensemiconductor devices 10 and 20.

The plurality of bump electrodes 150 form a plurality ofexternal-connection terminals including antenna connection terminal 100,the plurality of radio frequency input terminals 110, radio frequencyoutput terminal 121, and control terminal 131. Each of the plurality ofbump electrodes 150 is disposed on principal surface 91 b of moduleboard 91, and protrudes in the z-axis negative direction from principalsurface 91 b. The plurality of bump electrodes 150 each have an end thatis connected to an input/output terminal and/or a ground electrode, etc.on a motherboard located in the z-axis negative direction relative toradio frequency module 1.

It should be noted that each of the components on module board 91 isconnected to a pad electrode (not illustrated) or the like on moduleboard 91 and/or other components via bonding wire 161, for example. InFIG. 2, some of bonding wires 161 bonded to semiconductor device 50 areillustrated as examples, and illustration of the other bonding wires 161is omitted.

1.3 Advantageous Effects, Etc.

As described above, radio frequency module 1 according to the presentembodiment includes module board 91; semiconductor device 10 containingpower amplifier 11 and power amplifier 12, power amplifier 11 beingconfigured to amplify a radio frequency signal of communication band A,power amplifier 12 being configured to amplify a radio frequency signalof communication band B, communication band B being different fromcommunication band A; and semiconductor device 50 containing controlcircuit 55 configured to control power amplifier 11 and power amplifier12. In radio frequency module 1, semiconductor device 10 andsemiconductor device 50 are stacked together and disposed on moduleboard 91.

According to the-above described configuration, since semiconductordevice 10 and semiconductor device 50 can be stacked together, it ispossible to reduce the area of module board 91 and thus to achieveminiaturization of radio frequency module 1. In addition, sincesemiconductor device 50 containing control circuit 55 that controlspower amplifiers 11 and 12 and semiconductor device 10 containing poweramplifiers 11 and 12 are stacked, it is possible to reduce the lengthsof the lines between control circuit 55 and power amplifier 11 andbetween control circuit 55 and power amplifier 12. As a result, it ispossible to inhibit a control signal that passes through the linebetween control circuit 55 and power amplifier 11 or the line betweencontrol circuit 55 and power amplifier 12 from flowing into a radiofrequency signal as noise. In particular, under a condition that acontrol signal is a digital signal, it is possible reduce the inflow ofa digital noise into a radio frequency signal. As a result, it ispossible to improve electrical characteristics (e.g., noise figure (NF),gain characteristics, etc.) of radio frequency module 1.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, in a plan view of module board 91, the footprint ofsemiconductor device 50 may overlap both the footprint of poweramplifier 11 and the footprint of power amplifier 12 in semiconductordevice 10.

According to this configuration, it is possible to further reduce thelengths of the lines between control circuit 55 and power amplifier 11and between control circuit 55 and power amplifier 12. As a result, theinflow of noise into a radio frequency signal due to a control signalcan further be reduced, and thus it is possible to further improve theelectrical characteristics of radio frequency module 1.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, in a plan view of module board 91, the footprint ofsemiconductor device 50 may overlap each of the footprint of amplifyingelement 11 a that corresponds to an input stage of power amplifier 11and the footprint of amplifying element 12 a that corresponds to aninput stage of power amplifier 12.

According to this configuration, it is possible to overlap semiconductordevice 50 with the input stages of power amplifiers 11 and 12, allowingsemiconductor device 50 to be spaced from the output stages of poweramplifiers 11 and 12. In a power amplifier, in general, the amount ofheat generated by the input stage is larger than the amount of heatgenerated by the output stage. Accordingly, it is possible to reduce therisk of failure of semiconductor device 50 due to heat emitted from theoutput stages of power amplifiers 11 and 12.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, in a plan view of module board 91, the footprint ofsemiconductor device 50 may overlap neither the footprint of amplifyingelement 11 b that corresponds to an output stage of power amplifier 11nor the footprint of amplifying element 12 b that corresponds to anoutput stage of power amplifier 12.

According to this configuration, it is possible to space semiconductordevice 50 from the output stages of power amplifiers 11 and 12. As aresult, it is possible to reduce the risk of failure of semiconductordevice 50 due to heat emitted from the output stages of power amplifiers11 and 12.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, semiconductor device 10 may be disposed on moduleboard 91, and semiconductor device 50 may be stacked on semiconductordevice 10.

According to this configuration, it is possible to dispose, on moduleboard 91, semiconductor device 10 that contains power amplifiers 11 and12. As a result, it is possible to easily dissipate the heat generatedby power amplifiers 11 and 12 via module board 91.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, semiconductor device 50 may further contain switch51 including terminal 511 connected to an output terminal of poweramplifier 11 and terminal 512 connected to an output terminal of poweramplifier 12.

According to this configuration, it is possible to stack switch 51connected to the output terminals of power amplifiers 11 and 12 on poweramplifiers 11 and 12. Accordingly, it is possible to reduce the lengthsof the lines between switch 51 and power amplifier 11 and between switch51 and power amplifier 12. As a result, mismatching loss due to wiringloss or wiring variation can be reduced, and thus it is possible tofurther improve the electrical characteristics of radio frequency module1.

In addition, for example, radio frequency module 1 according to thepresent embodiment may further include switch 54 including terminal 541connected to an input terminal of power amplifier 11 and terminal 544connected to an input terminal of power amplifier 12, and semiconductordevice 10 and switch 54 may be disposed on mutually opposite surfaces ofmodule board 91.

According to this configuration, semiconductor device 10 and switch 54can be disposed on both surfaces of module board 91, and thus it ispossible to promote miniaturization of radio frequency module 1.

In addition, for example, radio frequency module 1 according to thepresent embodiment may further include a plurality of bump electrodes150 as a plurality of external-connection terminals, module board 91 mayinclude principal surface 91 a and principal surface 91 b on oppositesides of module board 91, semiconductor device 10 and semiconductordevice 50 may be disposed on principal surface 91 a, and the pluralityof bump electrodes 150 and switch 54 may be disposed on second principalsurface 91 b.

According to this configuration, switch 54 connected to the inputterminals of power amplifiers 11 and 12 can be disposed on principalsurface 91 b on which the plurality of bump electrodes 150 are disposed.As a result, switch 54 can be disposed in proximity to bump electrodes150 that receive radio frequency transmission signals from RFIC 3, andthus it is possible to reduce the lengths of the lines between bumpelectrodes 150 and switch 51.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, in a plan view of module board 91, the footprint ofswitch 54 may overlap the footprint of semiconductor device 10.

According to this configuration, it is possible to reduce the length ofeach of the line between switch 54 and power amplifier 11 and the linebetween switch 54 and power amplifier 12. As a result, mismatching lossdue to wiring loss or wiring variation can further be reduced, and thusit is possible to further improve the electrical characteristics ofradio frequency module 1.

In addition, for example, in radio frequency module 1 according to thepresent embodiment, each of power amplifier 11 and power amplifier 12may be a multistage amplifier, and in a plan view of module board 91,the footprint of switch 54 need not overlap the footprint of amplifyingelement 11 b that corresponds to an output stage of power amplifier 11or the footprint of amplifying element 12 b that corresponds to anoutput stage of power amplifier 12.

According to this configuration, it is possible to space switch 54 fromthe output stages of power amplifiers 11 and 12. As a result, it ispossible to reduce the risk of failure of switch 54 due to heat emittedfrom the output stages of power amplifiers 11 and 12. In addition, undera condition that a heat transfer path is formed from the output stagesof power amplifiers 11 and 12 to the mother board, it is possible toprevent the heat transfer path from being blocked by switch 54.

In addition, for example, radio frequency module 1 according to thepresent embodiment may further include low noise amplifier 21, andsemiconductor device 10 and low noise amplifier 21 may be disposed onmutually opposite surfaces of module board 91.

According to this configuration, semiconductor device 10 and low noiseamplifier 21 can be disposed on the both surfaces of module board 91,and thus it is possible to promote miniaturization of radio frequencymodule 1. In addition, since module board 91 is located between poweramplifiers 11 and 12 and low noise amplifier 21, it is possible toimprove the isolation characteristics between power amplifiers 11 and 12and low noise amplifier 21.

In addition, for example, radio frequency module 1 according to thepresent embodiment may further include a plurality of bump electrodes150 as a plurality of external-connection terminals, module board 91 mayinclude principal surface 91 a and principal surface 91 b on oppositesides of module board 91, semiconductor device 10 and semiconductordevice 50 may be disposed on principal surface 91 a, and the pluralityof bump electrodes 150 and low noise amplifier 21 may be disposed onprincipal surface 91 b.

According to this configuration, it is possible to dispose poweramplifiers 11 and 12 on principal surface 91 a and dispose low noiseamplifier 21 on principal surface 91 b. As a result, the heat transferpath from power amplifiers 11 and 12 to the motherboard can be easilyensured, and thus it is possible to improve the heat dissipationproperty of power amplifiers 11 and 12.

In addition, communication device 5 according to the present embodimentincludes: RFIC 3 configured to process a radio frequency signal; andradio frequency module 1 configured to transfer the radio frequencysignal between RFIC 3 and antenna 2.

According to this configuration, communication device 5 can yieldadvantageous effects equivalent to the advantageous effects yielded byradio frequency module 1.

Embodiment 2

Next, Embodiment 2 will be described. The present embodiment isdifferent from the above-described Embodiment 1 mainly in that atransmission IN switch is also contained in semiconductor devices thatare stacked. Hereinafter, the present embodiment will be describedfocusing on the points of difference from the above-described embodiment1, with reference to the drawings.

It should be noted that the circuit configuration of a semiconductormodule according to the present embodiment is equivalent to the circuitconfiguration of the above-described Embodiment 1, and thus theillustration and description of the circuit configuration will beomitted.

2.1 Component Arrangement of Radio Frequency Module 1A

The following describes in detail the component arrangement of radiofrequency module 1A, with reference to FIG. 4 and FIG. 5.

FIG. 4 illustrates a plan view of radio frequency module 1A according toEmbodiment 2. In FIG. 4, (a) illustrates a view when principal surface91 a of module board 91 is viewed from the z-axis positive side, and (b)illustrates a view when principal surface 91 b of module board 91 isviewed through from the z-axis positive side. FIG. 5 illustrates across-sectional view of radio frequency module 1A according toEmbodiment 2. The cross-sectional surface of radio frequency module 1Aillustrated in FIG. 5 is a cross-sectional surface taken along line v-vof FIG. 4.

As illustrated in FIG. 4 and FIG. 5, radio frequency module 1A furtherincludes module board 91, ground electrode pattern 92, resin components94 and 95, shielding electrode layer 96, and a plurality of postelectrodes 150A, in addition to the circuit components that contain thecircuit elements illustrated in FIG. 1. It should be noted thatillustration of resin components 94 and 95 and shielding electrode layer96 is omitted in FIG. 4.

As illustrated in (a) in FIG. 4, semiconductor device 10 that containspower amplifiers 11 and 12, semiconductor device 50A that containsswitches 51 and 54 and control circuit 55, and duplexers 61 to 63 aredisposed on principal surface 91 a.

Semiconductor device 50A is stacked above semiconductor device 10 in thesame manner as semiconductor device 50 according to Embodiment 1.

As illustrated in (b) in FIG. 4, semiconductor device 20 that containslow noise amplifier 21 and switch 52, and switches 53 are disposed onprincipal surface 91 b.

Resin component 94 is disposed on principal surface 91 a of module board91, and covers the circuit components on principal surface 91 a. Resincomponent 95 is disposed on principal surface 91 b of module board 91,and covers the circuit components on principal surface 91 b. Resincomponents 94 and 95 each have a function of ensuring reliability suchas a mechanical strength and moisture resistance of the componentsdisposed on principal surfaces 91 a and 91 b.

Shielding electrode layer 96 is a metal thin film formed by sputtering,for example, to cover an upper surface and side surfaces of resincomponent 94 and side surfaces of module board 91 and resin component95. Shielding electrode layer 96 is set to a ground potential, andinhibits an exogenous noise from entering the circuit componentsincluded in radio frequency module 1A.

The plurality of post electrodes 150A form a plurality ofexternal-connection terminals including antenna connection terminal 100,the plurality of radio frequency input terminals 110, radio frequencyoutput terminal 121, and control terminal 131. Each of the plurality ofpost electrodes 150A is disposed on principal surface 91 b of moduleboard 91, and extends perpendicularly from principal surface 91 b. Inaddition, each of the plurality of post electrodes 150A penetratesthrough resin component 95, and one end thereof is exposed from resincomponent 95. The one end of each of the plurality of post electrodes150A exposed from resin component 95 is connected to an input/outputterminal and/or a ground electrode, etc. on a motherboard located in thez-axis negative direction relative to radio frequency module 1A.

It should be noted that each of the components on module board 91 isconnected to a pad electrode (not illustrated) or the like on moduleboard 91 and/or other components via a bump electrode, for example.

2.2 Advantageous Effects, Etc.

In addition, for example, in radio frequency module 1A according to thepresent embodiment, semiconductor device 50A may further contain switch54 including terminal 541 connected to an input terminal of poweramplifier 11 and terminal 544 connected to an input terminal of poweramplifier 12.

According to this configuration, it is possible to stack switch 54connected to the input terminals of power amplifiers 11 and 12 on poweramplifiers 11 and 12. As a result, it is possible to reduce the lengthsof the lines between switch 54 and power amplifier 11 and between switch54 and power amplifier 12. As a result, mismatching loss due to wiringloss or wiring variation can be reduced, and thus it is possible tofurther improve the electrical characteristics of radio frequency module1A.

OTHER EMBODIMENTS

Although the radio frequency module and the communication deviceaccording to the present disclosure have been described above based onthe embodiments, the radio frequency module and the communication deviceaccording to the present disclosure are not limited to the foregoingembodiments. The present disclosure also encompasses other embodimentsachieved by combining arbitrary structural elements in theabove-described embodiments, variations resulting from variousmodifications to the above-described embodiments that may be conceivedby those skilled in the art without departing from the essence of thepresent disclosure, and various devices that include the above-describedradio frequency module and the above-described communication device.

For example, in the circuit configurations of the radio frequency moduleand the communication device according to each of the foregoingembodiments, another circuit element and line, for example, may beinserted in a path connecting circuit elements and a signal path whichare disclosed in the drawings. For example, an impedance matchingcircuit may be inserted between switch 53 and each of duplexers 61 to63. The impedance matching circuit can be implemented by an inductorand/or a capacitor, for example.

It should be noted that, although semiconductor devices 50 or 50A isstacked above semiconductor device 10 according to the above-describedembodiments, the present disclosure is not limited to thisconfiguration. More specifically, the up-down relationship between thetwo semiconductor devices is not limited, and it is sufficient ifsemiconductor device 10 and semiconductor device 50 or 50A are stackedtogether and disposed on module board 91. Accordingly, semiconductordevice 10 may be stacked on semiconductor device 50 or 50A. It ispossible to achieve miniaturization of radio frequency module 1 or 1A inthis case as well.

It should be noted that, although at least switch 51 and control circuit55 are contained in semiconductor device 50 or 50A stacked onsemiconductor device 10 according to the above-described embodiments,the present disclosure is not limited to this configuration. Forexample, in each of the above-described embodiments, semiconductordevice 50 or 50A may contain only switch 54, and switch 51 and controlcircuit 55 need not necessarily be contained in semiconductor device 50or 50A. In other words, it is sufficient if at least one of switch 51,switch 54, or control circuit 55 is contained in semiconductor device 50or 50A. In other words, only arbitrary one of, arbitrary two of, or allof switch 51, switch 54, and control circuit 55 may be contained in eachof semiconductor device 50 and 50A. In any case, it is possible toachieve miniaturization of the radio frequency module.

It should be noted that, although circuit components are disposed onboth surfaces of module board 91 according to the above-describedembodiments, the present disclosure is not limited to thisconfiguration. For example, in Embodiment 1, semiconductor device 20that contains low noise amplifier 21 and switch 52, and switches 53 and54 may also be disposed on principal surface 91 a of module board 91. Inaddition, for example, in Embodiment 2, semiconductor device 20 andswitch 53 may also be disposed on principal surface 91 a of module board91.

It should be noted that the arrangement of the components according toeach of the above-described embodiments is one example, and the presentdisclosure is not limited to this example. For example, in Embodiment 1,semiconductor devices 10 and 50 may be disposed on principal surface 91b, and semiconductor device 20 may be disposed on principal surface 91a.

Although only some exemplary embodiments of the present disclosure havebeen described in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of the present disclosure. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable widely to communication apparatusessuch as mobile phones as a radio frequency module disposed in afront-end unit.

The invention claimed is:
 1. A radio frequency module, comprising: amodule board; a first semiconductor device containing a first poweramplifier configured to amplify a radio frequency signal of a firstcommunication band and a second power amplifier configured to amplify aradio frequency signal of a second communication band, which isdifferent from the first communication band; a second semiconductordevice containing a control circuit configured to control the firstpower amplifier and the second power amplifier; and a low noiseamplifier, wherein the first semiconductor device and the secondsemiconductor device are stacked together and disposed on the moduleboard, and the first semiconductor device and the low noise amplifierare disposed on mutually opposite surfaces of the module board.
 2. Theradio frequency module of claim 1, wherein in a plan view of the moduleboard, a footprint of the second semiconductor device overlaps both afootprint of the first power amplifier and a footprint of the secondpower amplifier.
 3. The radio frequency module of claim 2, wherein in aplan view of the module board, a footprint of the second semiconductordevice overlaps each of an input stage of the first power amplifier andan input stage of the second power amplifier.
 4. The radio frequencymodule of claim 3, wherein in a plan view of the module board, thefootprint of the second semiconductor device does not overlap afootprint of an output stage of the first power amplifier or a footprintof an output stage of the second power amplifier.
 5. The radio frequencymodule of claim 1, wherein the first semiconductor device is disposed onthe module board, and the second semiconductor device is stacked on thefirst semiconductor device.
 6. The radio frequency module of claim 1,wherein the second semiconductor device contains a switch including afirst terminal connected to an output terminal of the first poweramplifier and a second terminal connected to an output terminal of thesecond power amplifier.
 7. The radio frequency module of claim 1,wherein the second semiconductor device contains a switch including afirst terminal connected to an input terminal of the first poweramplifier and a second terminal connected to an input terminal of thesecond power amplifier.
 8. The radio frequency module of claim 1,further comprising: a switch including a first terminal connected to aninput terminal of the first power amplifier and a second terminalconnected to an input terminal of the second power amplifier.
 9. Theradio frequency module of claim 8, wherein the first semiconductordevice and the switch are disposed on mutually opposite surfaces of themodule board.
 10. The radio frequency module of claim 9, furthercomprising: a plurality of external-connection terminals, wherein themodule board includes a first principal surface and a second principalsurface on opposite sides of the module board, and the firstsemiconductor device and the second semiconductor device are disposed onthe first principal surface.
 11. The radio frequency module of claim 10,wherein the plurality of external-connection terminals and the switchare disposed on the second principal surface.
 12. The radio frequencymodule of claim 8, wherein in a plan view of the module board, afootprint of the switch overlaps a footprint of the first semiconductordevice.
 13. The radio frequency module of claim 12, wherein each of thefirst power amplifier and the second power amplifier is a multistageamplifier.
 14. The radio frequency module of claim 13, wherein in a planview of the module board, the footprint of the switch does not overlap afootprint of an output stage of the first power amplifier or a footprintof an output stage of the second power amplifier.
 15. The radiofrequency module of claim 1, further comprising: a plurality ofexternal-connection terminals, wherein the module board includes a firstprincipal surface and a second principal surface on opposite sides ofthe module board, and the first semiconductor device and the secondsemiconductor device are disposed on the first principal surface. 16.The radio frequency module of claim 15, wherein the plurality ofexternal-connection terminals and the low noise amplifier are disposedon the second principal surface.
 17. A communication device, comprising:a signal processing circuit configured to process a radio frequencysignal; and the radio frequency module configured to transfer the radiofrequency signal between the signal processing circuit and an antenna,wherein the radio frequency module includes a module board; a firstsemiconductor device containing a first power amplifier configured toamplify a radio frequency signal of a first communication band and asecond power amplifier configured to amplify a radio frequency signal ofa second communication band, which is different from the firstcommunication band; a second semiconductor device containing a controlcircuit configured to control the first power amplifier and the secondpower amplifier; and a low noise amplifier, wherein the firstsemiconductor device and the second semiconductor device are stackedtogether and disposed on the module board, and the first semiconductordevice and the low noise amplifier are disposed on mutually oppositesurfaces of the module board.
 18. A radio frequency module, comprising:a module board including a first principal surface and a secondprincipal surface on opposite sides of the module board; a firstsemiconductor device disposed on the first principal surface andcontaining a first power amplifier configured to amplify a radiofrequency signal of a first communication band and a second poweramplifier configured to amplify a radio frequency signal of a secondcommunication band, which is different from the first communicationband; a second semiconductor device stacked on the first semiconductordevice and containing a control circuit configured to control the firstpower amplifier and the second power amplifier; and a low noiseamplifier, wherein the first semiconductor device and the low noiseamplifier are disposed on mutually opposite surfaces of the moduleboard.
 19. The radio frequency module of claim 18, wherein in a planview of the module board, a footprint of the second semiconductor deviceoverlaps both a footprint of the first power amplifier and a footprintof the second power amplifier.